Muscles: Actions, Origins & Insertions Questions and Graded Answers, 100% Guarantee

Muscles: Actions, Origins & Insertions Questions and Graded Answers,
100% Guarantee


Frontalis - Action: raises eyebrows
Origin: galea aponeurotica
Insertion: eyebrow skin, bridge of nose


Masseter - Action: closes jaw; elevates mandible
Origin: zygomatic arch
Insertion: mandibular ramus


Occipitalis - Action: pulls scalp posteriorly
Origin: galea aponeurotica {thin sheet of connective tissue}
Insertion: galea aponeurotica {thin sheet of connective tissue}


Orbicularis Oculi - Action: closes, blinks and squints eyes
Origin: medial margin of orbit
Insertion: skin around eyelids


Orbicularis Oris - Action: closes mouth; kissing muscle
Origin: maxilla and mandible
Insertion: lips


Sternocleidomastoid - Action: rotates head, head flexion
Origin: clavicle and manubrium of sternum
Insertion: mastoid process of temporal bone

, Sternohyoid - Action: depresses larynx and hyoid bone
Origin: clavicle and manubrium of sternum
Insertion: hyoid bone


External Intercostals - Action: elevates ribs
Origin: inferior border of each rib
Insertion: superior border of each rib


Temporalis - Action: closes jaw, elevates mandible
Origin: temporal bone
Insertion: coronoid process of mandible


Zygomaticus - Action: retracts and elevates upper lip
Origin: zygomatic bone
Insertion: skin on lateral sides of the mouth


Pectoralis Major - Action: flexion, adduction, and medial rotation at shoulder
Origin: ribs 2-6, sternum, and clavicle
Insertion: greater tubercle of humerus


Pectoralis Minor - Action: protracts scapula
Origin: ribs 3-5
Insertion: coracoid process of scapula


Rhomboid Major - Action: adducts scapula
Origin: spinous processes of vertebrae
Insertion: vertebral border of scapula